初始化后，Const_iterator成员变量未指向向量成员变量的开头

我正在尝试为纸牌游戏Avalon实现贝叶斯估计器。游戏共有五轮，每轮最多包含五个不同玩家提出的五个建议。如果提议被接受，则玩家继续执行任务，然后游戏进入下一轮。在上一轮比赛结束之前，尚不知道哪5名球员将在下一轮比赛中提议球队。我想跟踪当前使用迭代器向团队提出建议的玩家，但最终它指向无处。具体来说，在要求的构造函数中round1，迭代器Round::proposer正确指向&PlayerA的开始Round::proposers。然而，当我这个实例（或它的？副本）添加到Game::rounds，那么团成员proposer的Game::rounds.back()点无门，即使团成员proposers仍然是正确的。为什么会这样呢？在执行期间，当然会在call期间引发读取访问冲突异常(*Round::proposer)->make_proposal();。对于冗长的问题，我深表歉意，但似乎需要两个间接级别才能产生此错误。

// Player.h
#include <string>

class Player
{
private:
    std::string name;
public:
    Player(std::string name) : name(name) {};
    void make_proposal() const {};
};

// Round.h
#include "Player.h"
#include <vector>

class Round
{
private:
    std::vector<const Player*> proposers;
    std::vector<const Player*>::const_iterator proposer;
public:
    Round(std::vector<const Player*> proposers) : proposers(proposers), proposer(Round::proposers.begin()) {};

    void next_proposal() { (*Round::proposer)->make_proposal(); };
};

// Game.h
#include "Round.h"
#include <vector>

class Game
{
private:
    std::vector<Player*> players;
    std::vector<Player*>::iterator active_player;
    std::vector<Round> rounds;
public:
    Game(std::vector<Player*> players);

    void advance_player();
    void next_round();
};

// Game.cpp
#include "Game.h"

Game::Game(std::vector<Player*> players)
    : players(players), active_player(Game::players.begin())
{
    std::vector<Player*>::const_iterator player = Game::players.begin();
    std::vector<const Player*> proposers = { *player };
    for (unsigned int i = 0; i < 4; ++i) {
        ++player;
        if (player == Game::players.end()) player = Game::players.begin();
        proposers.push_back(*player);
    }

    Round round1(proposers);
    Game::rounds = { round1 };
}

void Game::next_round()
{
    Game::rounds.back().next_proposal();
}

#include <iostream>
#include "Game.h"

int main()
{
    Player playerA("A");
    Player playerB("B");
    Player playerC("C");
    Player playerD("D");
    Player playerE("E");
    Player playerF("F");

    std::vector<Player*> players = { &playerA, &playerB, &playerC, &playerD, &playerE, &playerF };
    Game game(players);

    for(unsigned int i = 0; i < 5; ++i) {
        game.next_round();
    }
}

令人惊讶的是，替换了两行代码

Round round1(proposers);
Game::rounds = { round1 };

在Game.cpp与

Round* round1 = new Round(proposers);
Game::rounds = { *round1 };

解决了这个问题，尽管我真的不明白为什么。毕竟，rounds是的成员变量，Game并且存在直到实例game被销毁为止。此hack的后续问题：round1上一个代码片段中指向的实例Game是否被类的默认构造函数破坏了，因为在添加到成员变量之前已取消引用该实例？